Drive mechanism and head rail for a blind

Abstract

A head rail for a vertical blind, the head rail being elongate and having a drive mechanism at one end for selectively tilting and retracting slats of the vertical blind along the length of the head rail, the drive mechanism including a rotatable tilt drive for tilting slats, a rotatable retract drive for retracting and deploying slats, and a transmission for rotating the tilt drive and the retract drive by means of a single rotatable source, wherein the transmission includes a clutch for rotating the tilt drive, the clutch incorporating a lost motion mechanism whereby, after a predetermined number of rotations in the same direction, transmission by the clutch to the tilt drive is disengaged and wherein the transmission includes a control gear which is located at a position along the length of the head rail so that it can be meshed with teeth of an external drive source.

We claim:  
     
       1. A head rail and motor unit assembly for a vertical venetian blind having an array of retractable and tiltable slats, the assembly including: 
       an elongate head rail having a mechanism at one end for tilting or retracting the slats of the vertical blind along the elongate bead rail; the mechanism having a rotatable control gear, the rotation of which controls the tilting or retracting; wherein the control gear is located at a position along the elongate head rail for operative coupling with a motor unit having a toothed drive gear; wherein the head rail includes a housing forming a generally enclosed structure, the housing including an aperture, through which the control gear meshes with the teeth of said toothed drive gear; wherein the housing has a first elongate surface, from which the slats are adapted to extend and at least one other elongate surface in which the aperture is formed; and wherein  
       the motor unit is releasably attached to said at least one other elongate surface of the head rail.  
     
     
       2. The assembly according to  claim 1  wherein the motor unit is a generally elongate structure having an elongate attachment surface for mounting alongside the at least one other elongate surface. 
     
     
       3. The assembly according to  claim 1  wherein the mechanism is a drive mechanism including: a rotatable tilt drive for tilting the slats or a rotatable retract drive for retracting and deploying the slats; and a transmission for rotating the tilt drive or retract drive by rotating means; the transmission also including the control gear. 
     
     
       4. A head rail and motor unit assembly for a vertical venetian blind an array of retractable and tiltable slats, the assembly including: 
       an elongate head rail having a mechanism at one end for tilting or retracting the slats of the vertical blind along the elongate head rail; the mechanism having a rotatable control gear, the rotation of which controls the tilting or retracting; wherein the control gear is located at a position along the elongate head rail; wherein the head rail includes a housing forming a generally enclosed structure, the housing including an aperture, wherein the housing has an elongate surface, from which the slats are adapted to extend and at least one other elongate surface, in which said aperture is formed; and  
       a motor unit for detachable attachment to the at least one other elongate surface of the head rail; the motor unit having a toothed drive gear for meshing with the control gear through said aperture; and  
       the mechanism also including a lost motion mechanism comprising: first and second components relatively rotatable about a common axis; a spacer disposed between the first and second components; and a flexible elongate member having ends attached respectively to the first and second components; wherein relative rotation of the first and second components causes the flexible elongate member to wrap around the spacer such that the first and second components can rotate relative to one another by an amount determined by the length of the flexible elongate member; and wherein the lost motion mechanism is driven by the control gear to tilt or retract the slats.  
     
     
       5. The assembly according to  claim 4  wherein the control gear is rotatable about an axis parallel to the longitudinal extent of the head rail. 
     
     
       6. The assembly according to  claim 4  or  5  the mechanism includes: a rotatable tilt drive for tilting the slats or a rotatable retract drive for retracting and deploying the slats; and a transmission for rotating the tilt drive or retract drive by way of a single rotatable source. 
     
     
       7. The assembly according to  claim 6  wherein the transmission includes a clutch for rotating the tilt drive. 
     
     
       8. The assembly according to  claim 6  the retract drive is rotated by the transmission such that the retract drive is only rotated after a predetermined number of rotations of the transmission in the same direction; and wherein the lost motion mechanism is incorporated operatively between the retract drive and the transmission. 
     
     
       9. A vertical blind assembly including in combination an elongate head rail having opposite longitudinal ends, elongate top and rear side surfaces defined between the opposite longitudinal ends, an array of vertically disposed movable stats suspended from the head rail and a motor unit detachably mounted along one of the top and rear side surfaces of the head rail, wherein the head rail further includes a drive mechanism at one of its opposite longitudinal ends having a housing and at least one gear on said housing for controlling movement of said slats and wherein the motor unit includes a support structure and a drive gear on said support structure for releasably meshing with the at least one gear of the drive mechanism. 
     
     
       10. The vertical blind according to  claim 9 , wherein the housing includes an aperture through which the gears mesh. 
     
     
       11. The vertical blind according to  claim 9 , wherein the motor unit has an elongated attachment surface for mounting alongside one of the elongate top and rear surfaces of the head rail. 
     
     
       12. The vertical blind according to  claim 9 , wherein the motor unit includes a rotatable latch insertable through ah opening in the head rail. 
     
     
       13. The vertical blind according to  claim 9 , wherein the movement controlled by the at least one gear of the drive mechanism is a tilt and retract movement and wherein the drive mechanism includes a tilt drive and a retract drive. 
     
     
       14. The vertical blind according to  claim 13 , wherein the drive mechanism includes a lost motion mechanism operatively incorporated between the tilt drive and the retract drive. 
     
     
       15. A head rail and motor unit assembly for a vertical venetian blind having an array of retractable and tiltable slats, the assembly including: 
       an elongate head rail having a mechanism at one end for tilting or retracting the slats of the vertical blind along the elongate head rail; the mechanism having a rotatable control gear, the rotation of which controls the tilting or retracting; wherein the control gear is located at a position along the elongate head rail for operative coupling with a motor unit having a toothed drive gear; wherein the head rail includes a housing forming a generally enclosed structure, the housing including an aperture, through which the control gear meshes with the teeth of said toothed drive gear; wherein the housing has a first elongate surface, from which the slats are adapted to extend and at least one other elongate surface in which the aperture is formed; and wherein  
       the motor unit is releasably attached to said at least one other elongate surface of the head rail, wherein the motor unit is a generally elongate structure having an elongate attachment surface for mounting along side the at least one other elongate surface and wherein, proximate the aperture, the at least one other elongate surface has a non-circular opening proximate the drive gear, and the motor unit includes a rotatable latch extending from the attachment surface and insertable through the non-circular opening for rotation so as to secure the motor unit to the head rail.  
     
     
       16. The assembly according to  claim 15  further comprising a clip for holding the head rail at a position therealong and including a rotatable clip latch for selectively securing the clip to the motor unit at a position along its length. 
     
     
       17. The assembly according to  claim 16  wherein the motor unit includes a lipped channel along at least part of the length of the attachment surface and the clip latch includes a key portion which can be rotated so as to be secured in the lipped channel. 
     
     
       18. The assembly according to  claim 17  wherein the housing of the head rail includes a groove along at least part of the length of a surface opposite the at least one other parallel elongate surface and the clip includes a tongue for insertion into the groove. 
     
     
       19. A head rail and motor unit assembly for a vertical venetian blind having an array retractable and tiltable slats, the assembly including: 
       an elongate head rail having a mechanism at one end for tilting or retracting the slats of the vertical blind along the elongate head rail; the mechanism having a rotatable control gear, the rotation of which controls the tilting or retracting; wherein the control gear is located at a position along the elongate head rail for operative coupling with a motor unit having a toothed drive gear; wherein the head rail includes a housing forming a generally enclosed structure, the housing including an aperture, through which the control gear meshes with the teeth of said toothed drive gear; wherein the housing has a first elongate surface, from which the slats are adapted to extend and at least one other elongate surface in which the aperture is formed; and wherein  
       the motor unit is releasably attached to said at least one other elongate surface of the head rail, wherein the mechanism is a drive mechanism including; a rotatable tilt drive for tilting the slats or a rotatable retract drive for retracting and deploying the slats; and a transmission for rotating the tilt drive or retract drive by rotation means; the transmission also including the control gear, and wherein the drive mechanism further includes the rotatable tilt drive and the transmission includes a clutch for rotating the tilt drive; the clutch incorporating a first lost motion mechanism whereby, after a predetermined number of rotations in the same direction, transmission by the clutch to the tilt drive is disengaged.